Heat exchanger assembly and method of forming same



Jan. 3, 1967 J. A. METzGr-:R

HEAT EXCHANGER ASSEMBLY AND METHOD OF FORMING SAME Filed Jan. 14, 1965 MMWR f' HKMMT( i; Fg r 4L? 2% s:

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'United State-s rPatent O 3,295,598 HEAT EXCHANGER ASSEMBLY AND METHOD F FORMING SAME John A. Metzger, Glenview, Ill., assigner to` Stanley Knight Corporation, Des Plaines, lll., a corporation of Illinois Filed Jan. 14, 1965, Ser. No. 425,405 13 Claims. (Cl. 165-172) This invention relates to heat exchangers and has particular relation to the construction of a heat exchanger assembly.

Conventionally, in forming a heat exchanger, a plurality of pipes or conduits are prepositioned and a block of metal, such as aluminum, is cast about and within the the spaces between such conduits. Such assemblies have proved susceptible to diiculties in manufacture and use. One example of such diiculties lies in the necessity for prepositioning the tubes or pipes and holding the same in the desired position during the pouring or casting operation. Another difliculty results from the pouring of extremely hot metal into contact with such tubes, leading to efforts to preheat the tubes prior to the casting operation. A further diiculty results from the creation of internal voids within a cast block about the heat exchanger tubes, such voids creating the possibility that refrigerant and the material to be cooled, for example, may become intermixed if openings should occur in such tubes and be communicated through such voids. Another diiculty lies in the fact that the pouring or casting operation may cause individual tube segments to move slightly from the desired position, thus leading to variants in the amount of heat transfer occurring -across the entire structure. Additionally, the bursting of an exposed tube portion in prior assemblies which employ a cast housing block results in the necessity for discarding the entire assembly. Accordingly, it is a purpose of the invention to provide a heat exchanger assembly effective to overcome the foregoing diiculties.

Similarly, heat exchangers have been formed by soldering, brazing or otherwise attaching a plurality of tubes in contiguous relationship, but skilled Workmanship is required. Temperature transfer may also be accomplished by immersion of coils in a bath and by wrapping coils externally about a tank. It is a purpose of the invention to provide a simplified, easily constructed, economical temperature transfer assembly and method which shall be effective tofully accomplish the temperature transfer function of such prior devices.

Another purpose is to provide a heat exchanger assembly of minimum cost in construction and operation.

Another purpose is to provide a heat exchanger assembly including means for insuring identical spacing between heat exchanger tubes across the entire assembly.

Another purpose is to provide a heat exchanger assembly having maximum contact and heat transfer capacities.

Another purpose is to provide a heat exchanger assembly Which may be readily disassembled for repair or replacement of elements therein.

Another purpose is to provide a heat exchanger assembly including means preventing intermixing of uid o1 materials flowing therethrough.

Another purpose is to provide a heat exchanger assembly including elements effective to insure correct, uniform spacing during the construction of said assembly.

Another purpose is to provide a heat exchanger assembly including a plurality of intertting block elements formed of extruded aluminum.

Another purpose is to provide a method of forming a heat exchanger assembly at minimum cost and maximum effectiveness.

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Another purpose is to provide a method of forming a heat exchanger assembly wherein block elements are inserted among a plurality of tubes and said tubes are thereafter compressed.

Another purpose is to provide a method of forming a heat exchanger assembly which includes the steps of positioning a plurality of block elements in loosely intertting relationship with each other and with a plurality of heat exchanger tubes and thereafter pressing said block elements into interlitting contacting relationship.

Another purpose is to provide a method of forming a heat exchanger assembly which includes the steps of positioning a plurality of block elements in loosely intertting relationship with each other and with a plurality of heat exchanger tubes and thereafter pressing said block elements into interfitting contacting relationship and compressing a portion of said tubes between ladjacent block elements to insure effective temperature-transferring contact therebetween. v

Other purposes will appear from time to time during the course of the specification and claims.l

The invention is illustrated more or less diagrammatically in the accompanying drawings, wherein:

FIGURE l is a side elevation;

FIGURE 2 is a sectional view taken on the line 2-2 of FIGURE l;

FIGURE 3 is a detail view illustrating a portion of the invention; and

FIGURE 4 is a partial top plan view illustrating a detail of the invention.

Like parts are indicated by like numerals throughout the specification and drawings.

Referring now to the drawings, and particularly to FIGURE l thereof, it will be observed that a first conduit or tube 1 is bent upon itself to form a plurality of reverse hairpin turns, such as those indicated at 2. While nine such turns are shown, it will be realized that the number thereof may vary without departing from the nature and scope of the invention. A second tube 3 is shown in FIGURE 1. A corresponding number of turns 4 are formed in the tube 3 and the tube 3 is offset in one plane from the tube 1 while lying in a plane parallel to that occupied by the tube 1. While it does not appear in FIGURE 1, because -it is masked by tubel, a third tube 5 is shown in the cross-sectional view of FIGURE 2, it being understood that the tube 5 has an equal number of turns, such as those shown at 2 and 4, and that the tube 5 lies in a plane paralleling those of tubes 1 and 3 and in a plane aligned with that occupied by tube 1. While there is thus shown a set of three tubes, namely tubes 1, 3 and 5, it will be understood that the number thereof may vary beyond two without departing from the nature and scope of the invention. It is convenient, for example, to consider the tube 3 as carrying refrigerant, the tube 1 as carrying soda and the tube 5 as carrying water. Such arrangement is particularly useful, for example, in the soda fountain field.

A securing and temperature-transfer block is indicated generally by the numeral 10. The block 10 is comprised of a pair of end block members 11, 12. The end block members 11, 12 have substantially planar or smooth outer surfaces. The inner surface of the block 11 has a conformation including a pair of spaced generally V-shaped valleys or wells 13, 14. The wells 13, 14 have curved bottom sections 13a, 14a, respectively. Between the wells 13, 14 the block 11 has a central frusto-conical ridge portion 15. The end surface of ridge 15 is concave as indicated at 15a and terminates'at a point short of a line drawn between the upper ends of the outer Walls of valleys 13, 14.

Between the end block elements 11, 12 the member 10 includes a plurality of identically formed spacing and heat-transfer blocks 20, one of which is illustrated in FIGURE 3. Each of the blocks 20 has one of its surfaces formed in the manner described above with respect to end block 11, i.e. such surface includes the valleys 13, 14 and the central ridge 1S with the curved surfaces 13a, 14a, 15a. The opposite surface of each of the blocks 20, however, is formed to include a pair of spaced frustoconical ridges 21, 22 with a V-shaped valley 23 formed therebetween. The valley 23 has a curved bottom surface 23a which extends to a point inwardly beyond the base of the ridges 21, 22. Each of the ridges 21, 22 is inwardly spaced from the adjacent side wall surface 20a and 2Gb, respectively, of the block 20. The outer end surface of the ridges 21, 22 is concaved as indicated at 21a, 22a. It Will be observed that the surfaces 13a, 21a are coaxial and that the same is true of the surfaces 14a and 22a 'and of the surfaces 15a and 23a. Similarly, the inclined side walls of ridges 21 and 22 are inclined at identical angles with the side walls of valleys 13, 14 and that the side walls of ridge 15 are inclined at angles identical with those of the valley 23. Hence the ridges 21, 22 of a given block 20 are formed and adapted for smooth, continuous mating temperature-transfer contact with the valleys 13, 14 of an adjacent block and the ridge 15 is formed and adapted for smooth, continuous mating temperaturetransfer contact with the walls of valley 23 of an adjacent block. It will be noted that the corners adjacent the concave surfaces 15a, 21a and 22a are rounded and that opposite parallel surfaces 20c, 20d are dimensioned and positioned for mating contact with corresponding surfaces of adjacent blocks. Hence the ridges 21, 22 of a particular block 20 may be mated with the valleys 13, 14 of block 11; a series of blocks 20, the number varying as may be desired without departing from the nature and scope of the invention, may then be sequentially mated with the ridges 21, 22 of each subsequent block mating with the valleys 13, 14 of an adjacent block and ridgesV 21, 22 of block 12 may be mated with the valleys 13, 14 of the last such block 20. It will be noted that the block 12 has a smooth outer surface and an inner surface bearing the ridges 21, 22 with valley 23 therebetween. Y

It will be noted, for example as indicated at 30, that the portions of the tubes 1, 3, 5, which are between opposed surfaces of adjacent block elements 20, have been deformed therebetween from a normally circular crosssectional configuration into a slightly oval cross-sectional configuration providing maximum temperature-transfer contact between adjacent blocks and the tube portions therebetween. A slight owing of the material of the tubes 1, 3, is permitted to occur into the limited space created by the curved edges of the ridge concaves 21a, 22a, 15a. Similarly, the contact surfaces between ad- 'jace'nt blocks 20 are substantial and close fitting to pro- 'vide for maximum heat-transfer from refrigerant tube 3 through the aluminum of blocks 11, 12 and 20 to the tubes 1, 5.

It will be understood, of course, that the contact and heat-transfer association of the end blocks 11, 12 with adjacent blocks 20 corresponds to the association of individual adjacent blocks 20.

Surrounding the outer smooth surfaces of the blocks 11, 20, 12 is a strap or securing member 40. The strap 40 is of continuous lextension and formed of suitable metal subject, for example, to Welding. The opposite ends 41, 42 of the strap 40 are brought into opposed relationship after the strap 40 has been wrapped or bent about the plurality of the blocks 11, 20, 12 and the edge portions 41, 42 are secured together, preferably by welding, as indicated at 43. The welding of the edge portions 41, 42 causes a shrinkage in the material of strap 40 and a consequent tightening thereof about and against the blocks 11, 20, 12.

The method of forming the heat exchanger of the invention comprises the steps of positioning a plurality of heat exchanger coils, such as those formed by the tubes 1, 3, 5, in substantially the spaced position desired, thereafter inserting between adjacent individual coils thereof a sufficient number of blocks 20 to provide for contact with aligned central portions of each of said coils. End blocks 11, 12 are then positioned in contact with the end portions of the tubular coils and the strap 40 is placed about the plurality of blocks 20 and end blocks 11, 12. The strap 40 is then drawn together to compress the blocks 11, 20, 12 into full contact position with each other and to compress the portions of the tube coils trapped between opposed surfaces of said blocks, to deform said tube portions and to provide maximum heat-transfer contact between said tube portions and the blocks in contact therewith and between the individual blocks, the` blocks being identical and automatically providing uniform spacing between all tube portions within the assembly block thus formed.

The individual blocks 11, 20, 12 are formed of ex-` truded aluminum. Hence a suicient number of block elements 11, 20, `12 may be formed and provided to equal an assembly block 10 of a particular size at a cost approximating one-third that of a cast block of said size.

If one of the tubes 1, 3, 5 should become damaged or burst, it is only necessary to disengage the strap 40, slide a suflicient number of the blocks 20 out of engagement with adjacent blocks and with adjacent coil portions, repair or replace the tube and replace the blocks.

new coil positioned to replace the defective coil, the blocks thereafter being repositioned between the coils and joined together by strap 40 as above described, the same being accomplished with a minimum of simple tools and manual effort. Since the block elements 11, 20, 12 are extruded, the problem of voids in the material of block 10 is eliminated. The contact surfaces of individual block elements is of substantial extension and suicient tightness as to provide full temperature-transfer across block 10 and to preclude the ow of material between parallel tube coils should a break occur in the tube coil portions enclosed within the assembly block 10. Since the block elements 11, 20, 12 are at room temperature, as are the tube coils 1 1, 3, 5, it will be seen that no temperature variance probi lem exists in the method or steps of forming the heat` exchanger.` Similarly, since the contacting portions of blocks 11, 2), 12 are identical, no possibility of variance in spacing between adjacent coils exists.

There is claimed:

1. A heat exchanger comprising a plurality of olset tube coils, a plurality of block elements, each of said block elements .being positioned adjacent and in direct heat-transfer contact with opposed portions of each of said tube coils, eachv of said tube coils having the entire outer surface of vits major portion in direct heat-transfer contact with opposed block element portions, each of said block elements being in heat-transfer contact with at` least one adjacent block element and means retaining all of said block elements in said direct heat-transfer contact relationship, whereby heat may be transferred from one to another of said tube coils through said block ele ments.

2. A temperature-transfer assent-bly including a plurality of tube coils, a plurlity of block elements inter-y spersed among said tube coils, means compressing said block elements into contact with said coils and with each other to form a substantially solid block, said block en If desired, all of the blocks may be separated and an entire i 4. A temperature-transfer assembly including a plurality of tube coils, a Iplurality of identical block elements interspersed among said tube coils, means compressing said block elements into contact with said coils and with each other to form a substantially solid block, said block enclosing substantially the entirety of said coils whereby temperature may be transferred from one to another of said coils through said block.

5. The structure of claim 4 wherein each said block element has a pair of substantially smooth side walls, and conformations formed on the opposite surfaces lbetween said side walls, the conformations formed on one of said surfaces including a pair of spaced, parallel ridges inwardly odset from said side walls and a valley formed between said ridges, the conformations of the opposite surface of said block including a pair of spaced valleys inwardly odset from said side walls and la ridge between said valleys.

6. The structure of claim 4 Iwherein each said block element has a pair of substantially smooth side walls, and conformations formed on the opposite surfaces between said side walls, the conformations formed on one of said surfaces including a pair of spaced, parallel ridges inwardly odset from said side walls and a Valley formed between said ridges, the conformations of the opposite surface of said block including a pair of spaced valleys inwardly odset from said side walls and a ridge between said valleys, the surfaces of said first-named ridges being formed and adapted for mating, heatatransfer contact with the surfaces of said last-named valleys, the surfaces of said first-named valley being formed and adapted for mating heat-transfer contact with the surfaces of said lastnamed ridge.

7. The structure of claim 4 wherein each said block element has a .pair of substantially smooth side walls, and conformations formed on the opposite surfaces between said side walls, the conformations formed on one of said surfaces including a pair of spaced, parallel ridges inwardly odset from said side walls and a valley formed between said ridges, the conformations of the opposite surface of said block including a pair of spaced valleys inwardly odset from said side Walls and a ridge between said valleys, said ridges having a height less than the depth of said valleys whereby a space is created when a set of said blocks is mated.

v8. The structure of claim 4 wherein each said block element has a pair of substantially smooth side walls, and conformations formed on the opposite surfaces between said side walls, the conformations formed on one of said surfaces including a pair of spaced, parallel ridges inwardly odset from said side walls and a valley formed between said ridges, the conformations of Ithe opposite surface of said block including a pair of spaced valleys inwardly odset from said side walls and a ridge between said valleys, said ridges having a lheight less than the depth of said valleys whereby a space is created when a set of said blocks is mated, said space having a width less than the diameter of the tubes to be enclosed therewithin.

9. The structure of claim 4 wherein each said block element has a pair of substantially smooth side walls, and conformations formed on the opposite surfaces between said side walls, the conformations formed on one of said surfaces including a pair of spaced, parallel ridges inwardly odset from said side walls and a valley formed between said ridges, the conformations of the opposite surface of said block including a pair of spaced valleys inwardly odset from said side walls a ridge between said valleys, said `first-named valley having a base pf' 1a tioned within the plane occupied by said side walls, s d last-named ridge having its end surface positioned within the plane occupied by said side walls. l

10. The method of forming a heat exchanger which comprises the steps of positioning a plurality of serpentine tube coils having alternating straight and curved portions in parallel, spaced, odset relationship, slidably positioning a plurality of solid block elements between opposed portions of said coils in loose contact with subf stantially the entirety of said tube straight portions and with each other, thereafter compressing said block elements together to bring each of said block elements into mating, lheat-transfer contact with adjacent block elements and with said tube coil portions and securing said block elements in said mating, heat-transfer Contact relationship.

11. The method of forming a heat exchanger whioh comprises the steps of positioning 'a plurality of tube coils having straight portions in parallel, spaced, odset relationship, enclosing said coil straight portions by placing a plurality of identical solid block elements among and about said coil portions, pressing said block elements together to form a substantially continuous solid block of heat-transfer material, to bring said block elements into mating, heat-transfer contact with each other and in heattransfer contact with portions of said coils therebetween.

1-2. The method of forming a heat exchanger which comprises the steps of positioning a plurality of tube coils in parallel, spaced, odset relationship, placing a plurality of identical block elements among said coils, pressing said `block elements together to form a substantially continuous solid block of heat-transfer material, to bring said block elements into mating, heat-transfer contact with each other and in heat-transfer contact with portions of said coils therebetween and to deform said coil portions.

113. The method of forming a heat exchanger which comprises the steps of positioning a plurality of tube coils in parallel, spaced, odset relationship, placing a plurality of identical block elements among said coils, pressing said block elements together to fonn a substantially continuous solid block of heat-transfer material, to bring said block elements into mating, heat-transfer contact with each other and in heat-transfer contact with portions of said coils therebetween and to deform said coil portions, and removably locking said block elements in said position.

References Cited by the Examiner UNITED STATES PATENTS 2,176,406 10/ 1939 McCullough 165-175 X 2,226,320 12/1940 ONeail 165--76 X 2,305,992 12/ 1942 Quillan 165--164 X 2,430,774 11/ 1947 Lynn 165--140 2,539,886 1/1951 Bisch 165-164 2,578,917 12/1951 Bisch 16S-104 2,677,255 5/1954 Wright 62-259 3,055,398 9/1962 Tunnessen 138-111 3,217,798 11/1965 Renzi 29-157.3 X

FOREIGN PATENTS 512,633 8/ 1939 Great Britain.

ROBERT A. OLEARY, Primary Examiner.

N- .R- WILSON, T- W- STREULE,

' .Assistant Examine@ Disclaimer 3,295,598.-J0m A. M etage/r, Glenview, IH. HEAT EXCHANGER ASSEM- BLY AND METHCD OF FORMING SAME. Patent dated J an. 3, 1967. Disclaimer filed Jan. 15, 1969, by the inventor and the assignee, Stanley Knight o'rpomtio'n. Hereby enter this disclaimer to claims l, 2, 3, 11, 12 and 13 of said patent.

[Oficial Gazette Jwne l, 1969.] 

1. A HEAT EXCHANGER COMPRISING A PLURALITY OF OFFSET TUBE COILS, A PLURALITY OF BLOCK ELEMENTS, EACH OF SAID BLOCK ELEMENTS BEING POSITIONED ADJACENT AND IN DIRECT HEAT-TRANSFER CONTACT WITH OPPOSED PORTIONS OF EACH OF SAID TUBE COILS, EACH OF SAID TUBE COILS HAVING THE ENTIRE OUTER SURFACE OF ITS MAJOR PORTION IN DIRECT HEAT-TRANSFER CONTACT WITH OPPOSED BLOCK ELEMENT PORTIONS, EACH OF SAID BLOCK ELEMENTS BEING IN HEAT-TRANSFER CONTACT WITH AT LEAST ONE ADJACENT BLOCK ELEMENT AND MEANS RETAINING ALL OF SAID BLOCK ELEMENTS IN SAID DIRECT HEAT-TRANSFER CONTACT RELATIONSHIP, WHEREBY HEAT MAY BE TRANSFERRED FROM ONE TO ANOTHER OF SAID TUBE COILS THROUGH SAID BLOCK ELEMENTS. 